Field of the Invention
[0001] The present invention relates to sugar derivatives comprising oxiranes or α,β-unsaturated
γ-lactones with pesticidal, particularly insecticidal, activity, to processes for
their preparation and their utilisation as pesticides, which are particularly effective
against fruit fly, domestic fly and white fly.
Background of the Invention
[0002] Compounds with the α,β-unsaturated γ-lactone moiety in their structure occur in the
plant kingdom, as metabolites of lichens and fungi,
1 as sesquiterpene derivatives
2 or as steroid glycosides.
3
[0003] Natural products possessing this structural element are also components of animal
species such as sponges.
4
[0004] Many of these compounds exhibit a variety of biologic activities such as antifungal,
insecticidal, antibacterial, phytotoxic and anti-inflammatory. Some of them are antibiotics,
potential anticancer agents and cyclooxygenase or phospholipase A
2 inhibitors.
5
[0005] Due to their biological importance, several synthetic methods have been developed
for the preparation of α,β-unsaturated γ-lactones. The synthesis of the endocyclic
lactones (α,β-butenolides) is reported in the literature, and includes mercuration-carbonylation
of propargylic alcohols,
6 condensation of 2,5-bis(trimethylsiloxy)furans with carbonyl compounds in the presence
of titanium tetrachloride
7 and various transformations of C
3 synthons, such as, for example, glycidaldehyde.
8
[0006] Other references report methods for the synthesis of γ-alkylideneα,β-butenolides
9 and for the preparation of α,β-butenolide derivatives with insect antifeedant activity.
10
[0007] A method for the preparation of the exocyclic type lactones involves the reaction
of 2-(bromomethyl)acrylic acid in the presence of indium with carbonyl compounds,
to give α-methylene-γ-butyrolactones in 7-96% yield.
11
[0008] Previous work reports the synthesis of butenolides through the condensation of sugar
epoxides with the dianion of phenylselenoacetic acid, followed by hydrolysis and subsequent
oxidation of the intermediate phenylselenolactone.
12,13,14 The nucleophilic opening of the oxirane is stereospecific, the configuration of the
stereogenic centre in the final lactone being determined by the centre of chirality
of the starting epoxide.
[0009] Another method for the synthesis of α,β-unsaturated γ-lactones involves a Reformatsky
type reaction of a ketosugar or a dialdofuranose with ethyl bromomethylacrylate and
zinc in THF under reflux.
13,14,15
[0010] Ethyl bromomethylacrylate and zinc-silver/graphite at -78°C have been successfully
applied to the synthesis of hydroxyesters from cyclic ketones,
16 ketosugars and a 2,3-
O-isopropylidene-D-erythronolactone
17 and to the synthesis of α,β-unsaturated γ-lactones from some ketosugars.
16
[0011] The synthesis of 3-ulosonic acids via a samarium iodide Reformatsky reaction of aldonolactones
was also reported.
18
[0012] Some of this type of compounds, reported in the literature, have fungicidal efficacy.
13
[0013] Epoxy sugars are versatile intermediates in organic synthesis, due to the ease of
their preparation from a variety of starting materials and due to their susceptibility
to reactions for example with electrophiles, nucleophiles, acids and bases. Furthermore,
epoxides are part of a range of compounds recognised as active principles, with biological
and pharmacological activity.
19 Reference can be made for example to cytotoxic metabolites, namely crotepoxide, pipoxide
and senepoxide, the latter playing an important role in plants as an antiparasitic
agent.
20
[0014] Methods for the preparation of epoxysugars use halohydrins as intermediate compounds,
21 and also aminosugars,
22 tosylates and/or mesylates,
23 vicinal diols,
24,25 glycals
26 and carbonyl compounds.
27
Summary of the Invention
[0015] This invention is related to the synthesis and pesticidal utilisation of compounds
of general formula (I) described further on.
[0016] These compounds possess efficacy as insecticides with high toxicity to fruit fly
(Drosophila melanogaster), house fly
(Musca domestica) and white fly
(Trialeurodes vaporarium).
[0017] On the other hand the compounds are not toxic to brine shrimps
(Artemia salina), the reference organisms in assays to evaluate the potential toxicity hazard to organisms
in ecosystems.
Detailed Description of the Invention
[0018] The first object of the invention is a family of compounds with pesticidal activity,
of general formula (I):
wherein
----- represents a carbon-carbon single or double bond;
----A- represents -CH(R4)-, if said carbon-carbon bond is a single bond,
wherein
- R4
- represents, independently, hydrogen, alkoxy or substituted alkoxy, or
- R1 and R4,
- taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
or
----A- represents =C(R5)-C(=O)-, if said carbon-carbon bond is a double bond,
wherein:
- R5
- represents hydrogen or halogen;
- R1 and R2
- represent, independently, hydrogen, halogen, alkoxy, substituted alkoxy or an ester
group; or
- R1 and R2,
- together with the carbon atoms to which they are attached, represent an oxirane ring;
or
- R1 and R2,
- taken together, represent an akylidenedioxy or substituted alkylidenedioxy group;
and
- R3
- represents -CH2R6,
wherein
R6 represents an ester group,
oxiranyl,
or a group of formula
wherein
- R7
- represents hydrogen or alkyl,
- R8
- represents phenylsulfanyl, phenylselenyl, phenylsulfoxy or phenylselenoxy, and
- R9
- represents hydrogen, ethoxycarbonyl or carbamoyl.
[0019] In a first embodiment, the invention relates to a subgroup of compounds within the
family of compounds of formula (I), wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
- R4
- represents, independently, hydrogen, alkoxy or substituted alkoxy, or
- R1 and R4,
- , taken together, represent an alkylidenedioxy or a substituted alkylidenedioxy group;
- R1 and R2
- represent, independently, hydrogen, alkoxy, substituted alkoxy or an ester group,
or
- R1 and R2,
- together with the carbon atoms to which they are attached, represent an oxirane ring;
or
- R1 and R2,
- taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
and
- R3
- represents a group of formula
wherein
R7 represents hydrogen or alkyl, and
R9 represents hydrogen, ethoxycarbonyl or carbamoyl.
[0020] Preferred within this subgroup are the compounds of general formula (IA):
wherein R
1, R
2, R
4, R
7 and R
9 have the meanings indicated for this first embodiment.
[0021] Especially preferred are the compounds of formula (IA), wherein R
1 and R
4, taken together, represent the isopropylidenedioxy group, R
2 represents benzyloxy, R
7 represents methyl and R
9 represents hydrogen.
[0022] Among these, the most especially preferred are the
D-gluco derivative,
i.e. 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-α-D-gluco-oct-6-enefuranurono-8,5-lactone
or the
D-alo derivative, i.e. 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-α-D-
alo-oct-6-enefuranurono-8,5-lactone.
[0023] Also particularly preferred are compounds of formula (IA), wherein R
1 and R
4, taken together, represent the isopropylidenedioxy group, R
2 represents benzyloxy and R
7 and R
9 represent hydrogen.
[0024] Among these, the most especially preferred are the
D-alo derivative,
i.e. 3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-α-D
-alo-oct-6-enefuranurono-8,5-lactone and the D-
gluco derivative, i.e. 3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-α-D-
gluco-oct-6-enefuranurono-8,5-lactone.
[0025] In a second embodiment, the invention relates to a subgroup of compounds within the
family of compounds of formula (I), wherein
----- represents a carbon-carbon double bond;
----A- represents =C(R5)-C(=O)-,
wherein,
- R5
- represents hydrogen or halogen;
- R1
- represents hydrogen or halogen; and
- R3
- represents -CH2R6,
wherein
R6 represents an ester group.
[0026] Preferred within this subgroup are the compounds of general formula (IB):
wherein R
1, R
2, R
5 and R
6 have the meanings indicated for this second embodiment.
[0027] Especially preferred are the compounds of formula (IB), wherein R
1 represents hydrogen, R
2 represents -OC(=O)CH
3, R
5 represents Br and R
6 represents -OC(=O)CH
3.
[0028] Among these, the most especially preferred is the D-
erythro derivative,
i.e. 4,6-di-
O-acetyl-2-bromo-2,3-dideoxy-D-
erythro-hex-2-ene-1,5-lactone.
[0029] In a third embodiment, the invention relates to a subgroup of compounds within the
family of compounds of formula (I), wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
- R4
- represents, independently, hydrogen, alkoxy or substituted alkoxy, or
- R1 and R4,
- , taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
- R1 and R2
- represent, independently, hydrogen, alkoxy or substituted alkoxy, or
- R1 and R2,
- together with the carbon atoms to which they are attached, represent an oxirane ring;
or
- R1 and R2,
- taken together, represent an alkylidenedioxy or a substituted alkylidenedioxy group;
and
- R3
- represents a group of formula
wherein
R7 represents hydrogen or alkyl,
R8 represents phenylsulfanyl, phenylselenyl, phenylsulfoxy or phenylselenoxy, and
R9 represents hydrogen, ethoxycarbonyl or carbamoyl.
[0030] Preferred within this subgroup are the compounds of general formula (IC):
wherein R
1, R
2, R
4, R
7, R
8 and R
9 have the meanings indicated for this third embodiment.
[0031] Especially preferred are the compounds of formula (IC), wherein R
1 and R
2, together with the carbon atoms to which they are attached, form an oxirane ring,
R
4 represents methoxy, R
7 represents methyl, R
8 represents phenylselenyl and R
9 represents hydrogen.
[0032] Among these, the most especially preferred is the 2,3-anhydro-β-L-
gulo derivative,
i.e. methyl (7
R)- and methyl (7
S)-2,3-anhydro-6,7-dideoxy-7-methyl-7-phenylselenyl-β-L-
gulo-octofuranurono-8,5-lactone.
[0033] Also especially preferred are compounds of formula (IC), wherein R
1 and R
4, taken together, form an isopropylidenedioxy group, R
2 represents hydrogen, R
7 represents methyl, R
8 represents phenylselenyl and R
9 represents hydrogen.
[0034] Among these, the most especially preferred is the D-
ribo derivative,
i.e. (7
R)- and (7
S)-3,6,7-trideoxy-1,2-
O-isopropylidene-7-methyl-7-phenylselenyl-α-D-
ribo-octofuranurono-8,5-lactone.
[0035] Especially preferred are also the compounds of formula (IC), wherein R
1 and R
4, taken together, form an isopropylidenedioxy group, R
2 represents benzyloxy, R
7 represents methyl, R
8 represents phenylselenyl and R
9 represents hydrogen.
[0036] Among these, the most especially preferred is the D-
gluco derivative,
i.e. (7
R)- and (7
S)-3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-7-methyl-7-phenylselenyl-α-D-
gluco-octofuranurono-8,5-lactone.
[0037] In a fourth embodiment, the invention relates to a subgroup of compounds, within
the family of compounds of formula (I), wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
- R4
- represents alkoxy or substituted alkoxy;
- R1 and R2,
- taken together with the carbon atoms to which they are attached, represent an oxirane
ring; and
- R3
- represents oxiranyl.
[0038] Preferred within this group are the compounds of general formula (ID):
wherein R
4 has the meaning indicated for this fourth embodiment.
[0039] Especially preferred are compounds of formula (ID), wherein R
4 represents methoxy.
[0040] Among these, the most preferred is the 2,3;5,6-dianhydro-β-L-gulo derivative, i.e.
methyl 2,3;5,6-dianhydro-β-L-gulofuranoside.
[0041] In a fifth embodiment, the invention relates to a subgroup of compounds, within the
family of compounds of formula (I), wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
- R4
- represents, independently, hydrogen, alkoxy or substituted alkoxy, or
- R1 and R4,
- , taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
or
- R1 and R2
- represent, independently, hydrogen, alkoxy or substituted alkoxy, or
- R1 and R2,
- taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
and
- R3
- represents oxiranyl.
[0042] Preferred within this subgroup are compounds of general formula (IE):
wherein R
1, R
2 and R
4 have the meanings indicated for the fifth embodiment.
[0043] A second object of the present invention is a process for the preparation of compounds
of formula (I).
Synthesis of compounds of Formula (IA)
[0044] Compounds of formula (IA) can be prepared by oxidation of phenylsulfanyllactones
with
m-chloroperbenzoic acid or with sodium metaperiodate, leading to the formation of sulfoxides
which, upon pyrolysis in toluene at reflux, provide the corresponding butenolides.
The transformation of the phenylselenyllactones into butenolides results from the
oxidation with hydrogen peroxide, under acid catalysis. This synthesis is summarized
in the following
Scheme 1.
[0045] In
Scheme 1, a lactone of formula (IC') [compound of formula (IC), wherein R
1 and R
4 represent, taken together, isopropylidenedioxy, R
2 represents benzyloxy, R
7 represents hydrogen or methyl, R
8 represents XPh, wherein X represents S or Se, and R
9 represents hydrogen] is converted into a butenolide of formula (IA') [compound of
formula (IA), wherein R
1 and R
4 represent, taken together, isopropylidenedioxy, R
2 represents benzyloxy, R
7 represents hydrogen or methyl and R
9 represents hydrogen]. This conversion is carried out in the presence of
m-chloroperbenzoic acid (when X represents S) and toluene at reflux, or in the presence
of hydrogen peroxide, in acid medium (when X represents Se), at temperatures between
-20°C and room temperature.
Synthesis of compounds of Formula (IB)
[0046] Compounds of formula (IB) can be prepared according to
Scheme 2.
[0047] In
Scheme 2, a compound of formula (II) is reacted with N-bromosuccinimide in the presence of
tetrahydrofuran and water, at a temperature of 10°C to 50°C, for a period of time
from 4 to 24 hours. In a second step the product obtained is added to molecular sieves
and pyridinium chlorochromate in dichloromethane, at a temperature of 10°C to 50°C,
for a period of time from 8 to 24 hours, to yield an α,β-unsaturated hexono-1,5-lactone
of formula (IB') [compound of formula (IB), wherein R
1 represents hydrogen, R
2 and R
6 represent acetoxy and R
5 represents bromo].
Synthesis of compounds of Formula (IC)
[0048] Compounds of formula (IC) can be prepared by reaction of the corresponding epoxide
precursor with dianions, namely: dianion of phenylselenoacetic acid, phenylselenopropionic
acid and phenylthioacetic acid, which upon cyclization in acid medium yield the corresponding
phenylselenyllactones or phenylsulfanyllactones, according to
Schemes 3a and
3b.
[0049] In
Scheme 3a, a diepoxide of formula (ID') [compound of formula (ID), wherein R
1 and R
2 represent, taken together, oxiranyl and R
4 represents methoxy] is converted into a lactone of formula (IC") [compound of formula
(IC), wherein R
1 and R
2 represent, taken together, oxiranyl, R
4 represents methoxy, R
7 represents hydrogen or methyl, R
8 represents XPh, wherein X represents S or Se, and R
9 represents hydrogen]. This conversion is carried out by treatment of (ID') with lithium
diisopropropylamide in tetrahydrofuran, at a temperature between -10°C and 10°C, followed
by reaction with a compound of formula PhXCHR
7CO
2H (wherein X represents S or Se e R
7 represents hydrogen or methyl).
[0050] In
Scheme 3b, following a procedure similar to that of
Scheme 3a, an epoxide of formula (IE') [compound of formula (IE), wherein R
1 and R
4 represent, taken together, isopropylidenedioxy and R
2 represents benzyloxy or hydrogen] is converted into a lactone of formula (IC"') [compound
of formula (IC), wherein R
1 and R
4 represent, taken together, isopropylidenedioxy, R
2 represents benzyloxy or hydrogen, R
7 represents hydrogen or methyl, R
8 represents XPh, wherein X represents S or Se, and R
9 represents hydrogen].
Synthesis of compounds of Formula (ID)
[0051] Compounds of formula (ID) can be prepared according to
Scheme 4.
[0052] In
Scheme 4, a compound of formula (III) is converted into a diepoxide of formula (ID") [compound
of formula (ID), wherein R
4 represents methoxy]. This conversion is carried out by treatment of a compound of
formula (III) with aqueous solution of potassium hydroxide and tetrahydrofuran, at
a temperature betwen 5°C and 40°C.
Synthesis of compounds of Formula (IE)
[0053] Compounds of formula (IE) can be prepared according to Scheme 5.
[0054] In
Scheme 5, a compound of formula (IV) is converted into an epoxide of formula (IE") [compound
of formula (IE), wherein R
1 and R
4 represent, taken together, isopropylidenedioxy and R
2 represents benzyloxy]. This conversion is carried out by conversion of compound of
formula (IV) with triphenylphosphane in benzene, followed by the addition of molecular
sieves and diethyl azodicarboxylate, at a temperature between 60°C and 100°C, for
a period of time of 1 to 4 days.
[0055] A third object of the instant invention is the use of compounds of formula (I) as
pesticides.
[0056] Preferably, these compounds are used as arthropodicides.
[0057] More preferably, these compounds are used as insecticides.
[0058] Still more preferably, these compounds are used with particular efficacy as insecticides
of high toxicity for controlling fruit fly
(Drosophila melanogaster), house fly
(Musca domestica) and white fly
(Trialeurodes vaporarium).
[0059] A fourth object of the invention is a method for controlling pests, namely arthropods,
particularly insects, especially fruit fly, house fly and white fly. Said method comprises
the application of an effective amount of compounds of formula (I) to said pests or
their locus.
EXPERIMENTAL
Preparation Examples
Example 1
Preparation of 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-α-D-gluco-oct-6-enefuranurono-8,5-lactone (1)
[0060] Glacial acetic acid (1 drop) was added to a solution of (7R)- and (7S)-3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-7-methyl-7-phenylselenyl-α-D-
gluco-octofuranurono-8,5-lactone (130 mg, 0.26 mmol) in anhydrous tetrahydrofuran (0.26
mL) at 0°C. 30% H
2O
2 (6.70 eq.) was added dropwise and the reaction mixture was stirred for 45 min at
0 °C. Extraction with a saturated solution of NaHCO
3 was followed by extraction with CH
2Cl
2 (3x2 mL). The organic phase was dried over sodium sulphate and evaporated under vacuum.
The residue was purified by low pressure column chromatography to provide the title
compound (45 mg, 64%) and unreacted starting material (26 mg, 20%); R
f: 0,40 (ethyl acetate/
n-hexane 1:4); [α]
= -22 (c 1.0; CHCl
3); IR (neat): 1770 (C=O), 1378 (C-O, isopropyl), 1662 (C=C) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.35-7.30 (m, 6H, H-6, Ph), 5.93 (d, 1H, H-1, J
1,2 = 3.6 Hz), 5.17 (dd, 1H, H-5, J
4,5 = 8.6 Hz, J
5,6 = 1.5 Hz), 4.69 (s, 2H, OCH
2Ph), 4.63 (d, 1H, H-2), 4.14 (d, 1H, H-3, J
3,4 = 3.0 Hz), 3.91 (dd, 1H, H-4), 1.93 (s, 3H, Me-7), 1.48 (s, 3H, Me, isopropyl), 1,25
(s, 3H, Me, isopropyl);
13C NMR (75.43 MHz, CDCl
3): δ 174.0 (C=O), 148.7 (C-6), 137.1 (Cq, Ph), 130.2 (C-7), 128.5; 128.1; 127.8 (Ph),
112.3 (Cq, isopropyl), 105.3 (C-1), 82.3 (C-2), 81.8 (C-3), 81.5 (C-4), 76.8 (C-5),
72.8 (OCH
2Ph), 10.7 (Me-7), 26.73 (Me, isopropyl), 26.11 (Me, isopropyl). Anal. calcd for C
19H
22O
6 (346.35): C 65.89; H 6.39; Found: C 65.57; H 6.45%.
Example 2
Preparation of 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-α-D-alo-oct-6-enefuranurono-8,5-lactone (2)
[0061] Following a procedure similar to that of Example 1, starting from (7R)- and (7
S)-3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-7-methyl-7-phenylselenyl-α-D-
gluco-octofuranurono-8,5-lactone
15 (100 mg, 0.2 mmol), the title compound was obtained (40 mg, 73% taking into account
the starting material that reacted), with recovery of unreacted starting material
(20 mg, 20%); R
f: 0.23 (ethyl acetate/
n-hexane 1:3); [α]
= +122 (c 1.0; CHCl
3); IR (neat): 1786 (C=O), 1384 (C-O, isopropyl), 1662 (C=C) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.41-7.30 (m, 5H, Ph), 7.25 (s, 1H, H-6), 5.77 (d, 1H, H-1, J
1,2 = 3.6 Hz), 5.16 (br s, 1H, H-5), 4.68; 4.64 (part A of AB system, OCH
2Ph, J
AB =12 Hz), 4.56 (t, 1H, H-2, J
2,3 = 4.4 Hz), 4.49; 4.45 (part B of AB system, 4.32 (dd, 1H, H-4, J
3,4 = 8.7 Hz, J
4,5 = 3.0 Hz), 3.65 (dd, 1H, H-3), 1.93 (s, 3H, Me-7), 1.55 (s, 3H, Me, isopropyl), 1.39
(s, 3H, Me, isopropyl);
13C NMR (75.43 MHz, CDCl
3): δ 173.8 (C=O), 145.3 (C-6), 136.9 (Cq, Ph), 130.4 (C-7), 128.5; 128.2; 128.0 (Ph),
113.3 (Cq, isopropyl), 104.1 (C-1), 79.3 (C-5), 78.6 (C-4), 72.1 (OCH
2Ph), 76.6 (C-2), 75.5 (C-3), 26.8 (Me, isopropyl), 26,5 (Me, isopropyl), 10.7 (Me-7).
Anal. calcd for C
19H
22O
6 (346.35): C 65.89; H 6.39; Found: C 65.63; H 6.48%.
Example 3
Preparation of 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-alo-oct-6-enefuranurono-8,5-lactone (3)
[0062] Following a procedure similar to that of Example 1, starting from (7R)- and (7S)-3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-7-phenylselenyl-α-D-
alo-octofuranurono-8,5-lactone
15 (130 mg, 0.3 mmol) the title compound was obtained (100 mg, 91%). R
f 0,60 (ethyl acetate/
n-hexane 1:1); [α]
= +47 (c 0,5; CH
2Cl
2); IR (KBr): 1774 (C=O), 1382 (C-O, isopropyl), 1662 (C=C) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.42 (d, H-6, J
6,7 = 6 Hz), 7.36-7.29 (m, 5H, Ph), 6.08 (dd, H-7, J
5,7 = 2.1 Hz), 5.7 (d, H-1, J
1,2 = 3.6 Hz), 5.28 (br s, H-5), 4.65; 4.61, 4.47 and 4.43 (AB system, OCH
2Ph, J
AB = 12 Hz), 4.51 (dd, H-2, J
2,3 = 4.2 Hz), 4.33 (dd, H-4, J
4,5 = 3.3 Hz, J
3,4 = 9 Hz), 3.62 (dd, H-3), 1.59 (s, 3H, Me, isopropyl), 1.35 (s, 3H, Me, isopropyl);
13C NMR (75,43 MHz, CDCl
3): δ 173.8 (C=O), 152.9 (C-6), 136.4 (Cq, Ph), 128.6; 128.3 (Ph), 121.9 (C-7), 112.0
(Cq, isopropyl), 104.3 (C-1), 86.8 (C-5), 81.5 (C-4), 78.5 (C-2), 72.2 (OCH
2Ph), 68.0 (C-3), 26.5 (Me, isopropyl), 26.3 (Me, isopropyl). Anal. calcd for C
18H
20O
6 (332.33): C 65.06; H 6.06; Found: C 65.05; H 6.29%.
Example 4
Preparation of 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-gluco-oct-6-enefuranurono-8,5-lactone (4)
[0063] Following a procedure similar to that of Example 1, starting from (7R)- and (7
S)-3-
O-benzyl-6,7-dideoxy-1,2-
O-isopropylidene-7-phenylselenyl-α-D-
gluco-octofuranurono-8,5-lactone
13,15 (112 mg, 0,23 mmol) the title compound was obtained (57,4 mg, 75%). R
f 0.32 (ethyl acetate/
n-hexane 1:4); m.p. = 66-70°C; [α]
= +0,2 (c 0,5; CHCl
3); IR (CHCl
3): 1758 (C=O), 1380 (C-O, isopropyl) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.71 (dd, H-6, J
6,7 = 5.9 Hz), 7.37-7.31 (m, 5H, Ph), 6.15 (dd, H-7, J
5,7 = 1.5 Hz), 5.92 (d, H-1, J
1,2 = 3.5 Hz), 5.30 (dd, H-5, J
5,6 = 1.5 Hz), 4.73 - 4.65 (AB system, OCH
2Ph, J
AB = 11 Hz), 4.63 (d, 1H, H-2), 4.15 (d, H-3, J
3,4 = 3.5 Hz), 3.97 (dd, H-4, J
4,5 = 6.7 Hz), 1.29 (s, 3H, Me, isopropyl), 1.43 (s, 3H, Me, isopropyl);
13C NMR (75.43 MHz, CDCl
3): δ 172.7 (C=O), 156.5 (C-6), 137.0 (Cq, Ph), 128.6; 128.3; 128.1 (Ph), 121.7 (C-7),
112.3 (Cq, isopropyl), 105.4 (C-1), 82.3 (C-2), 81.8 (C-3), 81.2 (C-4), 79.2 (C-5),
72.9 (OCH
2Ph), 26.8 (Me, isopropyl), 26.2 (Me, isopropyl). Anal. calcd for C
18H
20O
6 (332.33): C 65.06; H 6.06; Found: C 64.79; H 6.20%.
Example 5
Preparation of compound 4,6-di-O-acetyl-2-bromo-2,3-dideoxy-D-erythro-hex-2-enone-1,5-lactone (5)
[0064] N-bromosuccinimide (780 mg, 4.88 mmol) was added to a solution of tri-O-acetyl-D-glucal
(1 g, 3.67 mmol) in 370 mL tetrahydrofuran (THF) and 92 mL distilled water. The mixture
was stirred overnight at room temperature. The reaction mixture was poured into water
chilled at 0 °C, followed by extraction of the mixture thus obtained with diethyl
ether. The combined organic phases were dried over sodium sulphate, filtered and the
solvent was removed at reduced pressure to afford a syrup. The residue was then added
to a suspension of 3 Å molecular sieves (6.8 g) and pyridinium chlorochromate (4.4
g) in dichloromethane (20 mL). The reaction mixture was stirred at room temperature
overnight, eluted with diethyl ether and stirred at room temperature for 10 min. The
precipitate was removed by filtration and the filtrate was poured over florisil in
a filter and filtered under vacuum. The colourless filtrate was concentrated under
reduced pressure to provide the title compound as a syrup (760 mg, 37%). [α]
= +121 (
c 1, CH
2Cl
2); IR (neat): 1752 cm
-1 (C=O, lactone); 1632 cm
-1 (C=C);
1H NMR (300 MHz, CDCl3): δ 7.01 (d, 1H, H-3, J
3,4= 3.9 Hz); 5.30 (dd, 1H, H-4, J
4,5 = 6.6 Hz); 4.19, 4.17, 4.15, 4.13 (H-6a, part A of AB system, J
6a,6b = 12.6, J
5,6a = 4.5 Hz); 4.10, 4.08, 4.06, 4.04 (H-6b, part B of AB system, J
5,6b = 3.6 Hz); 1.91 (s, 3 H, acetyl CH
3); 1.85 (s, 3 H, acetyl CH
3);
13C NMR (75.43 MHz, CDCl
3): δ 170.1, 169.0 (acetyl C=O); 157.1 (lactone C=O); 142.3 (C-3); 116.4 (C-2); 77.7
(C-4); 64.8 (C-5); 61.6 (C-6), 20.4 (acetyl CH
3); Anal. calcd for C
10H
11O
6Br (307.08): C 39.12; H 3.61; Found: C 39.13; H 3.62%.
Example 6
Preparation of methyl (7R)-/(7S)-2,3-anhydro-6,7-dideoxy-7-methyl-7-phenylselenyl-β-L-gulo-octofuranurono-8,5-lactone (6A/6B)
[0065] A solution of
n-BuLi (1,6 M in
n-hexane, 5.43 mL, 8.7 mmol) was added dropwise to a solution of diisopropylamine (1.22
mL, 8.7 mmol) in anhydrous tetrahydrofuran (16 mL) under argon atmosphere at 0°C,
and the mixture was stirred at 0°C for 25 min. A solution of phenylselenoacetic, phenylselenopropionic
or phenylthioacetic acid (3.9 mmol) in anhydrous tetrahydrofuran (4 mL) was added
dropwise to the reaction mixture, keeping the temperature at 0°C and the mixture was
stirred for 1 h at 0°C. A solution of methyl 2,3;5,6-dianhydro-β-L-gulofuranoside
(compound of Example 9, 624 mg, 3.95 mmol) in anhydrous tetrahydrofuran (3 mL/g of
compound of Example 9) was then added dropwise and the reaction mixture was stirred
first at 0°C for 1h and then at room temperature for 16 h. After addition of a solution
of 50% acetic acid (10 mL) and heating under reflux for six hours, the mixture was
cooled to room temperature and neutralised with a saturated solution of NaHCO
3. After extraction of the mixture with diethyl ether (3x20 mL), the combined organic
phases were washed with water and dried over sodium sulphate. Evaporation of the solvent
under vacuum and purification by low pressure column chromatography, gave the title
compounds (460 mg, 32%,
6A/6B: 3/1). R
f= 0.23 (ethyl acetate/
n-hexane 1:1); IR (neat): 1784 (C=O), 1286 (C-O, epoxide) cm
-1;
1H NMR (300 MHz, CDCl
3) of
6A: δ 7.68-7.65 (m, 2H, Ph), 7.48-7.36 (m, 3H, Ph), 5.08 (s, 1H, H-1), 4.77 (ddd, 1H,
H-5, J
4,5 = 6,9 Hz, J
5,6a = 5.7 Hz, J
5,6b=10.5 Hz), 4.02 (d, 1H, H-4, J
34 = 6.6 Hz), 3.74 (d, 1H, H-3, J
2,3 = 2.7 Hz), 3.68 (d, 1H, H-2), 3.55 (s, 3H, OCH
3), 2.52 (dd, 1H, H-6a, J
6a,6b = 14.1 Hz), 2.32 (dd, 1H, H-6b), 1.66 (s, 3H, Me);
13C NMR (75.43 MHz, CDCl
3) of
6B: δ 176.0 (C-8), 137.7 (Cq, Ph), 129.7; 128.9 (Ph), 102.2 (C-1), 77.0 (C-4), 75.7
(C-5), 56.8 (OMe), 54.7 (C-2), 53.4 (C-3), 44.5 (C-7), 39.0 (C-6), 23.9 (Me). Anal.
calcd for C
16H
18O
5Se (369.25): C 52.04; H 4.90; Found: C 51.78; H 4.95%.
Example 7
Preparation of (7R)-/(7S)-3,6,7-Trideoxy-1,2-O-isopropylidene-7-methyl-7-phenylselenyl-α-D-ribo-octofuranurono-8,5-lactone (7A/7B)
[0066] Following a procedure similar to that of Example 6, starting from 5,6-anhydro-3-deoxy-1,2-
O-isopropylidene-α-D-
ribo-hexofuranose
15 (380 mg, 2.04 mmol), the title compounds were obtained (470 mg, 58%,
7A/7B: 7/3), after separation by column chromatography with ethyl acetate/
n-hexane (1:3) as eluent; R
f = 0.27 (ethyl acetate/
n-hexane (1:3); IR (KBr): 1754 (C=O), 1378 (CO, isopropyl) cm
-1;
1H NMR (300 MHz, CDCl
3) of
7A: δ 7.74-7.67 (m, 2H, Ph), 7.49-7.29 (m, 3H, Ph), 5.84 (d, 1H, H-1, J
1,2 = 3.3 Hz), 4.78 (t, 1H, H-2, J
2,3b = 3.9 Hz), 4.48-4.41 (ddd, 1H, H-5, J
4,5 = 5.1 Hz, J
5,6b = 10.1 Hz), 4.31-4.24 (ddd, 1H, H-4), 2.52 (dd, 1H, H-6a, J
5,6a = 5.5 Hz , J
6a,6b = 14.1 Hz), 2.27-2.14 (m, 2H, H-6b, H-3a), 1.73-1.66 (m, 4H, H-3b, Me), 1.53 (s,
3H, Me), 1.35 (s, 3H, Me).
13C NMR (75,43 MHz, CDCl
3) of
7B: δ 176.4 (C=O), 137.8 (Cq, Ph), 129.9; 129.1 (Ph), 111.6 (Cq, isopropyl), 105.6 (C-1),
80.2 (C-2), 78.6 (C-4), 76.9 (C-5), 44.7 (C-7), 40.5 (C-6), 35.1 (C-3), 26.7 (Me),
26.1 (Me), 24.0 (Me). Anal. calcd for C
18H
22O
5Se (397.30): C 54.41; H 5.57; Found: C 54.79; H 5.72%.
Example 8
Preparation of (7R)-/(7S)-3-O-Benzyl-6,7-dideoxy-1,2-O-isopropylidene-7- methyl-7-phenylselenyl-α-D-gluco-octofuranurono-8,5-lactone (8A/8B)
[0067] Following a procedure similar to that of Example 6, starting from 5,6-anhydro-3-
O-benzyl-1,2-
O-isopropylidene-α-D-glucofuranose (430 mg, 1.47 mmol), the title compounds were obtained
(590 mg, 79%,
8A/8B:1/2), after separation by chromatography with ethyl acetate/
n-hexane (1:6) as eluent; R
f = 0,49 (ethyl acetate/
n-hexane 1:6); IR (neat): 1773 (C=O), 1382 (C-O, isopropyl) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.67-7.63 (m, 4H, Ph), 7.41-7.26 (m, 16H, Ph), 5.95 (d, 1H, H-1
A, J
1,2 = 3.6 Hz), 5.90 (d, 1H, H-1
B, J
1,2 = 3.6 Hz), 4.83-4.17 (m, 7H, OCH
2Ph, H-2, H-5
A), 4.18 (dd, 1H, H-4
A, J
3,4 = 10.2 Hz, J
4,5 = 3.3 Hz), 4.09-4.05 (m, 2H, H-3), 3.78-3.75 (dd, 1H, H-4
B, J
3,4 = 7.2 Hz, J
4,5 = 3.3 Hz), 3.16 (d, 1H, H-5
B, J
5,6 = 3.9 Hz), 2.94 (dd, 1H, H-6a
B, J
5,6a = 3.9 Hz, J
6a,6b = 5.1 Hz), 2.79 (dd, 1H, H-6b
B, J
5,6b = 2.4 Hz), 2.59 (dd, 1H, H-6aA, J
5,6a = 5.7 Hz J
6a,6b = 14.4 Hz), 2.38 (dd, 1H, H-6b
A, J
5,6b = 9.9 Hz), 1.63 (s ,6H, Me-7), 1.51 (s, 6H, Me, isopropyl), 1,31 (s, 6H, Me, isopropyl);
13C NMR (75,43 MHz, CDCl
3): δ 176.7 (C=O), 137.6 (CqPh), 129.8; 129.0; 128.5; 128.1; 127.8; 127.6 (Ph), 112.1
(Cq-isopropyl), 105.2 (C-1), 82.6 (C-2), 82.5, 82.0 (C-3), 81.7, 81.5 (C-4), 73.1
(C-5
A), 72.6 (OCH
2Ph), 48.2 (C-5
B), 46.9 (CH
2-6
A), 45.0, 44.2 (C-7), 41.3 (CH
2-6
B), 26.8 (Me, isopropyl), 26.2 (Me, isopropyl), 24.0 (Me-7). Anal. calcd for C
25H
28O
6Se (503.42): C 59.65; H 5.60; Found: C 60.00; H 5.93%.
Example 9
Methyl 2,3;5,6-Dianhydro-β-L-gulofuranoside (9)
a) Preparation of methyl 2,5-di-O-tosyl-β-D-glucofuranoside
[0068] A solution of 1-
O-methyl-2,5-
O-ditosyl-β-D-glucofuranurono-6,3-lactone
29 (500 mg, 1 mmol) in tetrahydrofuran (10 mL) was added dropwise over 1h to a suspension
of LiBH
4 (42 mg,1,93 mmol) in tetrahydrofuran (5 mL), previously cooled to -10°C. The reaction
mixture was then stirred at +14°C for 16 h. After neutralisation with acetic acid
(50% in H
2O), filtration and concentration under reduced pressure a syrup was obtained which
was treated with MeOH (3x5 mL) and concentrated under vacuum. The residue was dissolved
in ethyl acetate and extracted with water. The organic phase was dried over sodium
sulphate and evaporated at reduced pressure. The residue was purified by column chromatography
with ethyl acetate/toluene (1:3) as eluent to give the title compound (472 mg, 94%).
R
f: 0,25 (ethyl acetate/toluene 1:3); [α]
= +44 (c 1, CHCl
3); IR (KBr): 3500 (OH) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.85-7.82 (m, 4H, Ph), 7.41-7.37 (m, 4H, Ph), 4.92-4.88 (m, 2H, H-1, H-5), 4.70
(s, 1H, H-2), 4.35 (t, 1H, H-3, J
3,OH = 8.1 Hz), 4,32 (dd, 1H, H-4, J
4,5 = 3.9 Hz, J
3,4 = 8.4 Hz), 3.90-3.82 (m, 2H, H-6a, H-6b), 3.31 (s, 3H, OCH
3), 2.46 (s, 3H, CH
3Ph), 2.45 (s, 3H, CH
3Ph);
13C NMR (75,43 MHz, CDCl
3): δ 145.0; 145.1 (Cq, Ph), 130.0; 129.8; 128.8; 127.9 (CH, Ph), 100.8 (C-1), 83.3
(C-2), 79.2 (C-5), 76.7 (C-4), 73.5 (C-3), 61.7 (C-6), 56.0 (OMe), 21.7 (CH
3, Ts). Anal. calcd for C
21H
26O
10S
2 (502.54): C 50.21; H 5.21; S 12.76; Found: C 50.23; H 5.30; S 12.65%.
b) Methyl 2,3;5,6-dianhydro-β-L-gulofuranoside
[0069] A solution of KOH (56 mg, 1.0 mmol) in water (1 mL) was cooled to +10°C and added
to a solution of methyl 2,5-di-O-tosyl-β-D-glucofuranoside (compound of step a)) (202
mg, 0.4 mmol) in water (4.0 mL) and tetrahydrofuran (1.0 mL), previously cooled to
+10°C. The reaction mixture was stirred at room temperature, until monitoring by thin
layer chromatography showed that the reaction was completed. After extraction with
CHCl
3 (10x10 mL), the combined organic phases were dried over sodium sulphate and concentrated
at reduced pressure. The residue was purified by column chromatography with ethyl
acetate/toluene (1:3) to provide the title compound (61 mg, 97%); R
f: 0.5 (ethyl acetate/
n-hexane 1/1); [α]
= +66 (c 0,5; CH
2Cl
2);
1H NMR (300 MHz, CDCl
3): δ 5.01 (s, 1H, H-1), 3.78 (d, 1H, H-4, J
4,5 = 6.0), 3.68-3.65 (m, 2H, H-2, H-3), 3.43 (s , 3H, OCH
3), 3.19 (ddd, 1H, H-5), 2.87 (dd, 1H, H-6a, J
5,6a = 4.2 Hz ), 2.75 (dd, 1H, H-6b, J
5,6b = 3 Hz, J
6a,6b = 6 Hz);
13C NMR (75,43 MHz, CDCl
3): δ 102.4 (C-1), 76.7 (C-4), 55.7 (OMe), 55.6 (C-2), 53.7 (C-3), 50.4 (C-5), 44.0
(C-6). Anal. calcd for C
7H
10O
4 (158.14): C 53.16; H 6.36; Found: C 53.13; H 6.35%.
Example 10
Preparation of 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-α-D-alofuranose
[0070] Triphenylphosphane (2.6 eq.) was added to a solution of 3-
O-benzyl-1,2-
O-isopropylidene-α-D-alofuranose
28 (2.40 g, 8.2 mmol) in benzene (143.5 mL) and the mixture was stirred at room temperature
for 15 min. After addition of powdered 3 Å molecular sieves (6.56 g), diethyl azodicarboxylate
(2.6 eq.) was added dropwise and the reaction mixture was stirred at 80°C for 48 h.
After filtration and evaporation of the solvent, the residue was purified by low pressure
column chromatography to provide the title compound (1.75 g, 73%) as a syrup after
purification by column chromatography with the system ethyl acetate/
n-hexane (1:3); R
f = 0.41 (ethyl acetate/
n-hexane 1:3); [α]
= +62 (c 1.0; CHCl
3); IR (neat): 1262 (C-O, epoxide), 1380 (C-O, isopropyl) cm
-1;
1H NMR (300 MHz, CDCl
3): δ 7.39-7.29 (m, 5H, Ph), 5.74 (d, 1H, H-1, J
1,2 = 3.6 Hz), 4.76; 4.72 (part A of AB system, OCH
2Ph, J
A,B = 11.7 Hz), 4.59-4.55 (m, 2H, H-2, OCH
2Ph, part B of AB system), 3.66 (dd, 1H, H-3, J
2,3 = 4.2 Hz, J
3,4 = 8.7 Hz), 3.19-3.16 (m, 1H, H-5), 4.20 (dd, 1H, H-4, J
4,5 = 3.0 Hz), 2.79-2.73 (m, 2H, H-6a, H-6b), 1.53 (s, 3H, Me), 1.37 (s, 3H, Me);
13C NMR (75,43 MHz, CDCl
3): δ 137.1 (Cq, Ph), 128.5; 128.3; 127.9 (Ph), 112.8 (Cq, isopropyl), 103.8 (C-1),
71.8 (OCH
2Ph), 77.5 (C-2), 77.0 (C-3), 76.5 (C-4), 50.4 (C-5), 44.2 (C-6), 26.6 (Me), 26.4 (Me).
Anal. calcd for C
16H
20O
5 (292.3): C 65.74; H 6.88; Found: C 65.40; H 6.88%.
Biological Activity of the Compounds
Materials and Methods for Determination of Biological Activity
[0071] A range of arthropod species was chosen to represent those in the terrestrial, aerial
and aquatic environment, covering important target pest groups such as house and fruit
flies and the white fly, which belongs to a group of agricultural and horticultural
pests.
Method A
Topical treatment of adult fruit fly (D. melanogaster)
[0072] A culture of fruit flies
(D. melanogaster) was used in the production of adult flies (approx 0.22 mg) of about seven days.
[0073] Serial dilutions of the compounds were prepared in acetone, and volumes of approximately
0.2 µL were applied to the ventral surface of each insect, using a calibrated PAX
100 microapplicator and a 1 mL syringe.
[0074] The fruit flies, in groups of 5, were anaesthetised using carbon dioxide. Prior to
recovery the flies were placed in a containing vial and kept at 30±1°C, for observations
of mortality at 1, 2, 3 and 24 hours after treatment.
[0075] For this purpose solutions of 6 different concentrations and a control were employed
in groups of 12 and 20 insects. Control mortalities were normally zero but occasionally
rose to 5-10%.
Method B
Second method for topical treatment of adult fruit flies
[0076] Different dilutions of the compounds in acetone were prepared and applied to individual
fruit flies using a Gilson piston micropipette.
[0077] Individual flies were held in padded forceps and 1 µL of acetone solution was applied.
The acetone was allowed to evaporate before placing the fly into the vial for observation,
kept at 30±1°C, following the standard methodology.
Method C
Method by feeding adult fruit fly (D. melanogaster)
[0078] Large glass vials were used which were fitted with caps, inside of which is inserted
a piece of cotton wool. This was soaked in a 10% sugar solution containing the test
compounds in a given concentration.
[0079] Care was taken to ensure that no solution dripped from the cotton wool and condensation
was avoided by keeping the vials at room temperature (25°C).
[0080] The fruit flies were anaesthetised using carbon dioxide and placed in the vials for
recovery and feeding.
Method D
Topical treatment of fruit fly larvae
[0081] Fruit fly larvae were separated from the growing medium and second and third instars
were topically treated with 0.2 µL acetone solutions of the compounds using a PAX
microapplicator.
[0082] Larvae were held in padded forceps for dosing and then placed on moistened filter
paper, at 30±1°C, for observation.
Method E
Topical treatment of house fly adults (M. domestica)
[0083] A culture of an insecticide-susceptible strain, Cooper, was established. Three-day-old
adult house flies (body weight about 1.8 mg) were anaesthetised with carbon dioxide.
Using the PAX microapplicator, a volume of 1 µL of acetone solution of the test compounds
was applied to the dorsal cuticle, holding the fly in padded forceps.
[0084] Groups of flies were placed into closed vials, kept at 30 ±1°C, for observation.
Method F
Immersion bioassay of brine shrimp A. salina larvae in brine
[0085] Freshly hatched brine shrimps were prepared by adding aquarium brine shrimp eggs
to salt water (15 g sea salt per litre water). The following day hatchlings were separated
from eggs and empty egg cases, using their phototropic movement and a Pasteur pipette.
[0086] Into each of a set of small glass vials was pipetted 195 µL of brine containing 5
shrimp larvae, using a micropipette. The solution of the test compound in 5 µL acetone
was added, the vial closed and kept at 30±1°C for observation.
[0087] Dead and alive shrimps were counted, at 1 and 24 hours after treatment, using a microscope.
Six concentrations and a control were used with 10 shrimps treated.
[0088] A blank test was performed for comparison of the results.
Method G
Foliar treatment of glasshouse white fly (T. vaporariorum)
[0089] Seedlings of tomato plants were infested with adult white fly. Selected leaves of
the tomato plants were excised and carefully trimmed to 3 leaflets without disturbing
the infestation. These were placed in glass tubes containing water and the leaflets
were then sprayed on both sides with a small sprayer delivering for each one 200 µL
of a solution of the test compound dissolved in 30% acetone in water.
[0090] Controls were sprayed with the solvent alone.
[0091] Counts of insects on the individual leaflets were made immediately after spraying
and then at 14 hours following.
Calculation of toxicity parameters
[0092] Dosages used in insect treatments were based upon the amount of compound applied
to each insect. For the shrimps the final concentrations of the compounds in the immersion
brine were used.
[0093] The 24 hour mortalities were used to calculate the LD
50/LC
50 using regression analysis of the probability percent mortality (probit) against log
dose/concentration.
30 This was calculated using PoloPC software (LeOra Software, Berkeley, CA, 1994).
[0094] Where single dose treatments were used (in the case of whitefly assays), no statistics
are available and the results are expressed as percent effect.
Results
Toxicity to fruit fly (D. Melanogaster)
[0095] The results of assays with fruit fly
D. Melanogaster are given in Table 1.
[0096] In the table are also given the confidence intervals at 95% for the LD
50 values, the number of organisms tested, the slope obtained by linear regression and
the index g (of significance). Data are considered satisfactory if g is substancially
less than 1 and seldom greater than 0.4.
31
[0097] As regards the confidence intervals for LD
50, the indication (90%) means that the intervals were calculated at 90% and not at
95%.
[0098] From the analysis of the LD
50 values, calculated through method 1, it is found that in general the compounds tested
are active against adult fruit flies, compounds of Examples 1, 2, 3 and 9 being extremely
active.
[0099] All of them are more active than imidacloprid, the reference insecticide for fruit
fly.
Table 1 -
Toxicity parameters of compounds tested on fruit flies according to methods A, B and
D. |
Compound No. |
LD50 (µg/insect) |
Confidence Intervals at 95% for LD50 (µg/insect) |
No. of Organisms Tested |
Slope |
g |
Method A |
1 |
0.00002 |
0.00000 - 0.00011 |
124 |
0.500±0.124 |
0.238 |
2 |
2.27x10 6 |
0.00000 - 0.00002 |
150 |
0.308±0.066 |
0.175 |
3 |
5.02x10-6 |
0.00000 - 0.00008 |
114 |
0.340±0.104 |
0.362 |
4 |
0.00012 |
n.d. |
114 |
0.385±0.109 |
0.860 |
5 |
0.00016 |
0.00000 - 0.00226 |
114 |
0.296±0.096 |
0.401 |
6 |
0.00015 |
0.00000 - 0.00092 |
114 |
0.696±0.155 |
0.484 |
7 |
0.00020 |
0.00000 - 0.00154 (90%) |
114 |
0.395±0.104 |
0.527 |
8 |
0.00037 |
n.d. |
|
0.453±0.115 |
0.967 |
9 |
0.00003 |
0.00000 - 0.00043 |
114 |
0.326±0.106 |
0.405 |
Imidacloprid |
0.01253 |
0.00523 - 0.01637 |
75 |
2.218±0.911 |
0.648 |
Method B |
2 |
0.00398 |
0.00000 - 0.2415 (90%) |
48 |
0.484±0.206 |
0.693 |
Method D |
5 |
4.74974 |
3.21963 - 20.59868 (90%) |
75 |
1.602±0.674 |
0.681 |
7 |
0.96796 |
0.72391 - 2.06494 |
75 |
2.624±0.810 |
0.366 |
n.d.- Data not available |
[0100] The fruit fly larvae are less sensitive to the toxins than adult flies.
[0101] The values of LD
50 obtained for the compounds of Examples 5 and 8 are much higher than those obtained
for the adult fly, therefore these compounds are less toxic for larvae than for adult
flies.
Toxicity to house fly M. domestica
[0102] Toxicity parameters for adult house flies, treated topically with compounds of Examples
5 and 8, are given in Table 2.
[0103] Although these insects are approximately 8 fold larger than fruit flies, analysis
of said table allows to conclude that the compounds tested are much less toxic (2
to 3 orders of magnitude) for this type of flies than for fruit flies.
[0104] LD
50 values correspond only to a moderate insecticidal activity.
Table 2 -
Toxicity parameters of compounds tested on adult house flies |
Compound No. |
LD50µg/insect) |
Confidence Intervals at 95% for LD50 (µg/insect) |
No. of Organisms Tested |
Slope |
g |
Method E |
5 |
1.06481 |
n.d. |
40 |
0.228±0.146 |
1.561 |
8 |
0.64404 |
n.d. |
30 |
0.383±0.182 |
0.863 |
Toxicity to brine shrimp
[0105] Toxicity parameters for assays in which brine shrimp larvae are exposed to the compounds
in saline solution are given in Table 3. Data obtained show good correlation (g <
0,4) and high LC
50 values, indicating a low toxicity for this type of organisms.
Table 3 -
Toxicity parameters of compounds tested on brine shrimp larvae, method F. |
Compound No. |
LC50 (µg/mL) |
Confidence Intervals at 95% for LC50 (µg/mL) |
No. of Organisms Tested |
Slope |
g |
Method F |
1 |
100.62 |
90.03 - 125.27 |
50 |
8.862±2.644 |
0.342 |
2 |
64.30 |
57.75 - 77.28 |
50 |
9.217±2.638 |
0.315 |
3 |
144.71 |
128.12 -172.71 |
50 |
7.763±2.182 |
0.303 |
4 |
358.92 |
324.89 - 400.42 |
60 |
9.770±2.057 |
0.170 |
5 |
38.36 |
8.244 - 3258.70 (90%) |
60 |
0.423±0.175 |
0.655 |
6 |
125.48 |
113.08 - 139.97 |
50 |
10.275±2.421 |
0.213 |
7 |
261.04 |
220.59 - 320.09 (90%) |
50 |
8.601±2.195 |
0.778 |
8 |
220.41 |
199.24 - 249.71 |
50 |
10.359±2.659 |
0.253 |
9 |
671.50 |
567.31 - 807.72 (90%) |
60 |
8.734±1.862 |
0.591 |
Imidacloprid |
0.03121 |
0.02387 - 0.04593 |
100 |
2.435±0.802 |
0.417 |
Insecticidal effect on adult white fly
[0106] The results of the bioassays of the insecticidal compounds on adult whiteflies
T. vaporariorum are given in Table 4. Five compounds were tested, which were applied spraying 600
µL of each compound solution (prepared according to method G) on the leaves of tomato
plants infested with a known number of adult whitefly. After 14 hours, the number
of dead insects (or eventually of insects that disappeared) was counted. These assays
were performed at room temperature, between 20 and 25°C.
[0107] From the data in Table 4, it is found that the compounds of Examples 4 and 9 show
efficacy as insecticides.
Table 4 -
Insecticidal effect againts adult white fly, assayed by spraying infested tomato leaves. |
Compound No. |
Concentration (µg/mL) |
% Control of White Fly |
3 |
1.3 |
0 |
4 |
2.5 |
50 |
6 |
1.3 |
0 |
7 |
4.8 |
0 |
9 |
2.5 |
85 |
Discussion and conclusions
[0108] Bioassays were performed using a range of compounds and treatment techniques in different
species of arthropods. Adult fruit flies, treated topically, showed high levels of
sensitivity to the compounds tested, such that the LD
50 values determined are much lower than that for the reference insecticide "imidacloprid".
However some variation was observed in the toxicity effect produced by the different
compounds.
[0109] The slope of the log-probit regression line was generally small and much smaller
than that for imidacloprid. When treated by incorporation into the adult diet the
compounds were much less toxic. Topical treatment of the larval stage was also much
less toxic but the regression line slope increased uniformly.
[0110] Some of the compounds were tested by topical application on adult house fly and were
much less toxic compared to the fruit fly adults.
[0111] The slopes of the log-probit regression line were similar to those obtained by the
same type of treatment used in adult fruit fly, suggesting a mechanism of action similar
although with less activity and some selectivity.
[0112] Contrary to the high insectividal activity found, the compounds have a very low toxicity
against brine shrimps.
[0113] The high values of LC
50 are associated with steep regression lines.
[0114] It can be concluded that these compounds show a very low toxicity towards this type
of organisms in saline medium, not producing toxicity in these ecosystems.
[0115] In the test of spraying the compounds on leaves infested with adult white flies the
compounds of Examples 4 and 9 were found to be promising for activity against the
white fly. These compounds also showed high toxicity against adult fruit flies.
References
[0116]
1. Haynes, L. J.; Plimmer, J. R Q. Rev. Chem. Soc. 1960, 14, 292-315.
2. Devon, T. K.; Scott, A. I. Handbook of Naturally Occurring Compounds; Academic Press: New York, 1972; Vol. II, pp. 79-175 (quoted in Ref. 8).
3. Marshall, P. G. In Chemistry of Carbon Compounds; Rodd, E. H., Ed.; Elsevier: New York, 1970; Vol. II D, Chapter 17 (quoted in Ref.
8).
4. (a) Schmitz, F. J.; Kraus, K. W.; Ciereszko, L. S.; Sifford, D. H.; Weinheimer,
A. J. Tetrahedron Lett. 1966, 7, 97-104; (b) Cimino, G.; De Stefano, S.; Minale, L.; Fattorusso, E. Tetrahedron 1972, 28, 333-341; (c) Cafieri, F.; Fattorusso, E.; Santacroce, C.; Minale, L.; Tetrahedron 1972, 28, 1579-1583; (d) Faulkner, D. J. Tetrahedron Lett. 1973, 14, 3821-3822; (e) Rothberg, I.; Shubiak, P. Tetrahedron Lett. 1975, 16, 769-722; (f) Cimino, G.; De Stefano, S.; Guerriero, A.; Minale, L. Tetrahedron Lett. 1975, 16, 1417-1420.
5. Ma, S.; Schi, Z. ; Yu, Z. Tetrahedron 1999, 55, 12137-12148.
6. Larock, R. C. ; Riefling, B.; Fellows, C. A. J. Org. Chem. 1978, 43, 131-137.
7. Brownbridge, P.; Chan, T. H. Tetrahedron Lett. 1980, 21, 3431-3434.
8. Cardellach, J.; Estopa, C.; Font, J.; Moreno-Mañas, M.; Ortuño, R. M.; Sachez-Ferrando,
F.; Valle, S.; Vilamajo, L. Tetrahedron 1982, 38, 2377-2394.
9. Kotora, M.; Negishi, E. Synthesis 1997, 121-128.
10. Klein Gebbinck, E. A.; Stork, G. A.; Jansen, B. J. M.; of Groot, A. Tetrahedron 1999, 55, 11077-11094.
11. Choudhury, P. K.; Foubelo, F.; Yus, M. Tetrahedron 1999, 55, 10779-10788.
12. Figueredo, M.; Font, J.; Virgili, A. Tetrahedron 1987, 43, 1881-1886.
13. Rauter, A. P.; Ferreira, M. J.; Font, J.; Virgili, A.; Figueredo, M.; Figueiredo,
J. A.; Ismael, M. I.; Canda, T. L. J. Carbohydr. Chem. 1995, 14, 929-948.
14. Rauter, A. P.; Figueiredo, J. A.; Ismael, M. I.; Pais, M. S.; Gonzalez, A. G.;
Dias, J.; Barrera, J. B. J. Carbohydr. Chem. 1987, 6, 259-272.
15. Rauter, A. P.; Figueiredo, J.; Ismael, M.; Canda, T. L.; Font, J.; Figueredo,
M. Tetrahedron: Asymmetry 2001, 12, 1131-1146.
16. Csuk, R.; Furstner, A.; Weidmann, H. J. Chem. Soc., Chem. Commun. 1986, 775.
17. Csuk, R.; Glänzer, B. I. ; Hu, Z.; Boese, R. Tetrahedron 1994, 50, 1111-1124.
18. Hanessian, S.; Girard, C. Synlett 1994, 10, 865-867.
19. Rao, A. S. Tetrahedron 1983, 39, 2323-2367.
20. Garem, B. Tetrahedron 1978, 34, 3353-3383.
21. Rodrigues, J.; Dulcere, J. P. Synthesis, 1993, 1177-1202.
22. Waggins, L. F. Nature, 1950, 165.
23. Ohle, M.; Vargha, L. V. J. Chem. Soc. 1959, 2717.
24. Mitsunobu, O. Synthesis 1981, 1.
25. Szeja, W. Synthesis 1985, 983-985.
26. Kwart, H.; Hoffman, D. M. J. Org. Chem. 1966, 31, 419-425.
27. Gutshe, C. D. Organic Reactions, 1954, 8, 364.
28. Rauter, A. P.; Figueiredo, J. A.; Ismael, M. I., Carbohydr. Res. 1989, 188, 19-24.
29. Dax, K.; Rauter, A. P.; Stütz, A. E.; Weidmann, H., Liebigs Ann. Chem. 1981, 1768-1773.
30. Robertson, J. L.; Preisher, H., Pesticide Bioassays with Arthropods, 1992, CRC Press, Boca Raton, FL.
31. Finney, D. J., Probit Analysis, 1972, 3rd Ed., Cambridge University Press, London, p. 79.
1. Pesticidal compound of formula (I)
wherein
----- represents a carbon-carbon single or double bond;
----A- represents -CH(R4)-, if said carbon-carbon bond is a single bond,
wherein
R4 represents, independently, hydrogen, alkoxy or substituted alkoxy, or
R1 and R4, taken together, represent an alkylidenedioxy or a substituted alkylidenedioxy
group; or
----A- represents =C(R5)-C(=O)-, if said carbon-carbon bond is a double bond,
wherein:
R5 represents hydrogen or halogen;
R1 and R2 represent, independently, hydrogen, halogen, alkoxy, substituted alkoxy or an ester
group; or
R1 and R2, together with the carbon atoms to which they are attached, represent an oxirane
ring; or
R1 and R2, taken together, represent an akylidenedioxy or substituted alkylidenedioxy group;
and
R3 represents -CH2R6,
wherein
R6 represents an ester group,
oxiranyl,
or a group of formula
wherein
R7 represents hydrogen or alkyl,
R8 represents phenylsulfanyl, phenylselenyl, phenylsulfoxy or phenylselenoxy, and
R9 represents hydrogen, ethoxycarbonyl or carbamoyl.
2. Pesticidal compound of formula (I) according to claim 1,
wherein
represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
R4 represents, independently, hydrogen, alkoxy or substituted alkoxy, or
R1 and R4, taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
R1 and R2 represent, independently, hydrogen, alkoxy, substituted alkoxy or an ester group,
or
R1 and R2, together with the carbon atoms to which they are attached, represent an oxirane
ring; or
R1 and R2, taken together, represent an alkylidenedioxy or a substituted alkylidenedioxy
group; and
R3 represents a group of formula
wherein
R7 represents hydrogen or alkyl, and
R9 represents hydrogen, ethoxycarbonyl or carbamoyl.
3. Pesticidal compound of formula (I) according to claim 2 having formula (IA)
wherein R
1, R
2, R
4, R
7 and R
9 are as defined in claim 2.
4. Compound according to claim 3, wherein R1 and R4, taken together, represent isopropylidenedioxy group, R2 represents benzyloxy, R7 represents methyl and R9 represents hydrogen.
5. Compound according to claim 4, which is a D-gluco derivative, i.e. 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-α-D-gluco-oct-6-enefuranurono-8,5-lactone.
6. Compound according to claim 4, which is a D-alo derivative, i.e. 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-α-D-alo-oct-6-enefuranurono-8,5-lactone.
7. Compound according to claim 3, wherein R1 and R4, taken together, represent an isopropylidenedioxy group, R2 represents benzyloxy and R7 and R9 represents hydrogen.
8. Compound according to claim 7, which is a D-alo derivative, i.e. 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-alo-oct-6-enefuranurono-8,5-lactone.
9. Compound according to claim 7, which is a D-gluco derivative, i.e. a 3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-α-D-gluco-oct-6-enefuranurono-8,5-lactone.
10. Pesticidal compound of formula (I) according to claim 1,
wherein
----- represents a carbon-carbon double bond;
----A- represents =C(R5)-C(=O)-,
wherein,
R5 represents hydrogen or halogen;
R1 represents hydrogen or halogen; and
R3 represents -CH2R6,
wherein
R6 represents an ester group.
11. Pesticidal compound of formula (I) according to claim 10, which has formula (IB)
wherein R
1, R
2, R
5 and R
6 are as defined in claim 10.
12. Compound according to claim 11, wherein R1 represents hydrogen, R2 represents -OC(=O)CH3, R5 represents Br and R6 represents -OC(=O)CH3.
13. Compound according to claim 12, which a D-erythro derivative, i.e. 4,6-di-O-acetyl-2-bromo-2,3-dideoxy-D-erythro-hex-2-ene-1,5-lactone.
14. Pesticidal compound of formula (I) according to claim 1,
wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
R4 represents, independently, hydrogen, alkoxy or substituted alkoxy, or
R1 and R4, taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
R1 and R2 represent, independently, hydrogen, alkoxy or substituted alkoxy, or
R1 and R2, together with the carbon atoms to which they are attached, represent an oxirane
ring; or
R1 and R2, taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
and
R3 represents a group of formula
wherein
R7 represents hydrogen or alkyl,
R8 represents phenylsulfanyl, phenylselenyl, phenylsulfoxy or phenylselenoxy, and
R9 represents hydrogen, ethoxycarbonyl or carbamoyl.
15. Pesticidal compound of formula (I) according to claim 14 having formula (IC)
wherein R
1, R
2, R
4, R
7, R
8 and R
9 are as defined in claim 14.
16. Pesticidal compound of formula (I) according to claim 15, wherein R1 and R2, taken together with the carbon atoms to which they are attached, form an oxirane
ring, R4 represents methoxy, R7 represents methyl, R8 represents phenylselenyl and R9 represents hydrogen.
17. Compound according to claim 16, which is a 2,3-anhydro-β-L-gulo derivative, i.e. methyl (7R)- and methyl (7S)-2,3-anhydro-6,7-dideoxy-7-methyl-7-phenylselenyl-β-L-gulo-octofuranurono-8,5-lactone.
18. Pesticidal compound of formula (I) according to claim 15, wherein R1 and R4, taken together, form an isopropylidenedioxy group, R2 represents hydrogen, R7 represents methyl, R8 represents phenylselenyl and R9 represents hydrogen.
19. Compound according to claim 18, which is a D-ribo derivative, i.e. (7R)- and (7S)-3,6,7-trideoxy-1,2-O-isopropylidene-7-methyl-7-phenylselenyl-α-D-ribo-octofuranurono-8,5-lactone.
20. Pesticidal compound of formula (I) according to claim 15, wherein R1 and R4, taken together, form an isopropylidenedioxy group, R2 represents benzyloxy, R7 represents methyl, R8 represents phenylselenyl and R9 represents hydrogen.
21. Compound according to claim 20, which is a D-gluco derivative, i.e. a (7R)- and (7S)-3-O-benzyl-6,7-dideoxy-1,2-O-isopropylidene-7-methyl-7-phenylselenyl-α-D-gluco-octofuranurono-8,5-lactone.
22. Pesticidal compound of formula (I) according to claim 1,
wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
R4 represents alkoxy or substituted alkoxy;
R1 and R2, taken together with the carbon atoms to which they are attached, represent an
oxirane ring; and
R3 represents oxiranyl.
23. Pesticidal compound of formula (I) according to claim 22 having formula (ID)
wherein R
4 is as defined in claim 22.
24. Pesticidal compound of formula (I) according to claim 23, wherein R4 represents methoxy.
25. Compound according to claim 24, which is 2,3;5,6-dianhydro-β-L-gulo derivative, i.e. methyl 2,3;5,6-dianhydro-β-L-gulofuranoside.
26. Pesticidal compound of formula (I) according to claim 1, wherein
----- represents a carbon-carbon single bond;
----A- represents -CH(R4)-,
wherein
R4 represents, independently, hydrogen, alkoxy or substituted alkoxy, or
R1 and R4, taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
or
R, and R2 represent, independently, hydrogen, alkoxy or substituted alkoxy, or
R1 and R2, taken together, represent an alkylidenedioxy or substituted alkylidenedioxy group;
and
R3 represents oxiranyl.
27. Pesticidal compound of formula (I) according to claim 27 having formula (IE)
wherein R
1, R
2 and R
4 are as defined in claim 26.
28. Process for the preparation of a compound of Formula I of any of claims 1 to 27, wherein:
a) for the preparation of compounds of formula (IA), a lactone of formula (IC') [compound
of formula (IC), wherein R1 and R4 represent, taken together, isopropylidenedioxy, R2 represents benzyloxy, R7 represents hydrogen or methyl, R8 represents XPh, wherein X represents S or Se, and R9 represents hydrogen] is converted into a butenolide of formula (IA') [compound of
formula (IA), wherein R1 and R4 represent, taken together, isopropylidenedioxy, R2 represents benzyloxy, R7 represents hydrogen or methyl and R9 represents hydrogen], according to the following scheme:
b) for the preparation of compounds of formula (IB), a compound of formula (II) is
converted into an α,β-unsaturated hexono-1,5-lactone of formula (IB') [compound of
formula (IB), wherein R1 represents hydrogen, R2 and R6 represent acetoxy and R5 represents bromine], according to the following scheme:
c) for the preparation of compounds of formula (IC) a precursor diepoxide of formula
(ID') [compound of formula (ID), wherein R1 and R2 represent, taken together, oxyranyl and R4 represents methoxy] is converted into a lactone of formula (IC") [compound of formula
(IC), wherein R1 and R2 represent, taken together, oxyranyl, R4 represents methoxy, R7 represents hydrogen or methyl, R8 represents XPh, wherein X represents S or Se, and R9 represents hydrogen], according to the following scheme:
or
the epoxide precursor of formula (IE') [compound of formula (IE), wherein R1 and R4 represent, taken together, isopropylidenedioxy and R2 represents benzyloxy or hydrogen] is converted into a lactone of formula (IC"') [compound
of formula (IC), wherein R1 and R4 represent, taken together, isopropylidenedioxy, R2 represents benzyloxy or hydrogen, R7 represents hydrogen or methyl, R8 represents XPh, wherein X represents S or Se, and R9 represents hydrogen], according to the following scheme:
d) for the preparation of compounds of formula (ID) a compound of formula (III) is
converted into a diepoxide of formula (ID") [compound of formula (ID), wherein R4 represents methoxy], according to the following scheme:
e) for the preparation of compounds of formula (IE), a compound of formula (IV) is
converted into an epoxide of formula (IE") [compound of formula (IE), wherein R1 and R4 represent, taken together, isopropylidenedioxy and R2 represents benzyloxy], according to the following scheme:
29. Use of a compound of formula (I) of any of the claims 1 to 27 as a pesticide.
30. The use of claim 29, wherein the pests are arthropods.
31. The use of claim 30, wherein the arthropods are insects.
32. The use of claim 31, wherein the insects are fruit fly (Drosophila melanogaster), house fly (Musca domestica) and white fly (Trialeurodes vaporarium).
33. A method for controlling pests, comprising the application of an effective amount
of compounds of formula (I) to said pests or their locus.
34. The method of claim 33, wherein the pests are arthropods.
35. The method of claim 34, wherein the arthropods are insects.
36. The method of claim 35, wherein the insects are fruit fly (Drosophila melanogaster), house fly (Musca domestica) and white fly (Trialeurodes vaporarium).